Improvements include an integrated, high output, direct-drive motor in the C-axis to replace the previous roller-drive system powering the 2,000 rpm turning table. The A-axis trunnion rotates through a 50 per cent larger angle, from +120 to -30°, allowing machining of features at the rear of components and facilitating loading and unloading of parts at the front of the machine.
In addition, the A-axis is now tilted by a backlash-free roller drive, promoting high accuracy metalcutting. A holding force of 400 Nm, without the need for a mechanical clamping mechanism, delivers high speed indexing combined with rigidity when milling parts at an angle or turning them in the horizontal plane.
A new option is a 16,000 rpm ‘BIG Plus’ face-and-taper contact spindle, which can be specified in place of the standard 10,000 rpm spindle. X, Y and Z travels of 200, 440 and 305 mm remain the same, but the distance between the table surface and the spindle nose has been increased to 455 mm.
Brother has driven down every conceivable element of non-productive time. For example, not only are speeds fast during non-cutting motions, but they also take place simultaneously in X, Y, Z, A and C, in parallel with tool change. Rapids of 50 m/min in the linear axes help to minimise non-cutting times further, while 30 m/min cutting feed rate maximises metal removal rate. A 0.9 second tool change from the 22-position magazine, giving 1.4-second chip-to-chip time, is another feature while synchronised tapping is world-leading at 377 m/min peripheral tap speed.
The spindle motor's rapid acc/dec and a responsive servo control enable a 0.2 second start/stop time, while start-up time of the turning table from zero to 2,000 rpm is less than 0.3 second.Accessibility for workpiece transfer is ergonomic and the generous door opening can be automated. A new, high speed C-00 control system completes the package.